Mates that are difficult for engines

bro I cant even find mate in 1 D:

how tf do you find mate in 37

A journey of a 1000 miles starts with a single step

Click the solution .

Here, I'll give you some gratuitous mates in 1 that you can solve.

Enjoy

Ok, just for you I have appended the PGN on this mate in 23 with several variations where the black King makes a different move than in the main line:

@drdos7

Puzzle 1. Ra8#

Puzzle 2. Bg7#

Puzzle 3. Qd7#

Puzzle 4. f7#

(PS. I might have annotated some of them wrong)

See, you CAN solve some mates in 1 afterall.

Here is a me being silly and creating a variation on the aforementioned mate in 23 theme. I put the White Queen on the square that the Black King ends up getting mated on, it ends up being a mate in 20, and heck Stockfish might even be able to solve it now on this one.

Another very amusing mate that engines have a little trouble with:

White to move and mate in 24:

This isn't so much a difficult one as it is an interesting question of choice, when a position has multiple choices, is it random or there a specific one an engine will always go. For example:

In this position white has exactly 101 moves that checkmate (any other move is a stalemate) which move does the engine choose and why? Will it choose the same move on multiple trials?

There is only one stalemate move with the black knight on the board. Without that knight the position is a draw. My own design engine picks the stalemate move as the best choice for white. Its planned release date is May 1st provided I can fix the flaws. ASAP

Oh yeah you're right I only put the knight there so the position is legal, was thinking without the knight.

Here's a mate in 66:

White to move and mate in 66

latest development version of Stockfish chooses 1.Qxh8 Mate every time as well as Crystal.

Probably because it's a capture. Remove the knight and see what it says.

I'm obviously missing something fundamental. What is it? (I could understand *without that knight the position is illegal.)

Is the fact your engine picks the draw one of the flaws to be fixed?

hmm

w/o the knight the position is a draw by stalemate as it is blacks move?

and it cant be whites move because what was blacks move

the king cant come from anywhere (illegal many check)

and the target position where white is to move, doesnt include any black pieces (except king) and so there is no "white captures a black piece" stuff

and maybe the design engine just has a flaw (it likes captures, and thinks stalemate is a win due to misprogramming? or its a multi variant engine and for some of them stalemate/ bare king is a win and that somehow slipped in?)

With the black Knight removed, Stockfish plays 1.Ne2 Mate consistantly.

Maybe that was the reasoning (but the text and FEN seem to suggest it's White to play).

Strictly speaking the GUI plays 1.Ne2# if the UCI interface is used. Probably because the knight is on c1 and that is the first square under the ordering αν≤α'ν' when α<α' (alphabetically) or α=α' (alphabetically) and ν≤ν' (numerically).